[ESNext] Implement DynamicImportCall

src/d8.h

Index: src/d8.h
diff --git a/src/d8.h b/src/d8.h
index 21e4c4f0833c9f26da1b49813c1606d3d06351b5..794257fbc4536b71dce21c4aaaea4065fb90e820 100644
--- a/src/d8.h
+++ b/src/d8.h
@@ -280,7 +280,6 @@ class Worker {
   base::Atomic32 running_;
 };
 
-
 class ShellOptions {
  public:
   ShellOptions()
@@ -440,7 +439,15 @@ class Shell : public i::AllStatic {
   static void SetUMask(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void MakeDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void RemoveDirectory(const v8::FunctionCallbackInfo<v8::Value>& args);
-
+  static void HostImportModuleDynamically(Isolate* isolate,
+                                          Local<String> referrer,
+                                          Local<String> specifier,
+                                          Local<Promise> promise);
+
+  // Data is of type DynamicImportData*. We use void* here to be able
+  // to conform with MicrotaskCallback interface and enqueue this
+  // function in the microtask queue.
+  static void DoHostImportModuleDynamically(void* data);
   static void AddOSMethods(v8::Isolate* isolate,
                            Local<ObjectTemplate> os_template);